A method of verifying torque measurements of a reaction torque transducer of an instrument drive unit includes a controller receiving a verification signal generating an acceptable range of torques receiving a torque signal comparing the torque signal to the acceptable range of torques and stopping a motor if the torque applied by the motor is outside of the acceptable range of torques. The verification signal is indicative of the current drawn by the motor and the torque signal is indicative of torque applied by the motor.
